Management of Stratified Databases

We propose here a knowledge based management system supporting immediate visualization and simulation facilities in presence of non-monotonic reasoning. It is based on a special class of indefinite deductive databases, called stratified databases, introduced in APT, BLAIR and WALKER [ABW] and VAN GELDER [VG], in which recursion "through" negation is disallowed. A stratified database has a natural model associated with it which is selected as its intended meaning. The main technical problem addressed here is the task of maintaining this model. To solve it we refine the ideas present in the works of DoYLE [DJ and DE KLEER [dK] on belief revision systems. We also discuss the implementation issues and the trade-offs involved.